How to Fax CRA Supporting Documents From Outside Canada

A practical guide to preparing and sending a document packet when your CRA letter permits fax submission.

LowFax.com · October 6, 2026 · 9 min read

LowFax.com · How to Fax CRA Supporting Documents From Outside Canada

A letter from the Canada Revenue Agency can ask you to supply receipts, forms, or other evidence. If you are outside Canada, the practical question is how to get the requested documents to the right office without finding a fax machine.

When the CRA permits fax for your particular request, you can prepare a digital document packet and use a browser-based sending service. Start with the letter: it tells you what the office needs and how to respond. This guide concerns requested supporting documents, rather than a general method for filing every Canadian tax return.

Does the CRA accept supporting documents by fax?

For benefits and credits reviews, the CRA's official submission guidance lists three options: online submission, fax to the number in the letter, or mail to the listed address. Its fax instruction is:

“by fax, to the number provided in the letter” — Canada Revenue Agency

The CRA also discusses fax in its tax-return review document guidance. Those instructions describe online portals and identify mail or fax as alternatives in certain document situations. Follow the guidance for your own review; do not transfer a number from an unrelated CRA program.

Read the request before preparing the packet

Make a checklist from the letter. Record the period involved, the documents requested, the reply deadline, the office or department, and any case or reference number. If something is unclear, use the contact details in that letter to ask the CRA before submitting.

A packet is easier to check when it follows the order of the request. If the letter asks for three kinds of evidence, group each kind together. A short explanatory page can identify the attachments and explain a missing item, but it should not replace evidence the office requires.

Confirm the Canadian fax number

Use the fax number designated for your request. A general contact number, a voice line, and a fax line are different things. If you have two letters with different numbers, establish which office is handling this response.

In LowFax.com, select Canada and check the complete destination shown in the form before payment. If the letter supplies a toll-free number and you are unsure whether it can be reached through your sending service, ask the receiving office for an internationally reachable fax number. Do not substitute a guessed number.

Prepare clear copies of the requested documents

• Scan paper pages or photograph them in even light, keeping the full page in view.
• Check dates, names, totals, and small print at a readable size.
• Save the completed forms, then reopen the exact file you intend to upload.
• Put attachments in the requested order and check for accidental duplicates.
• Preserve the original documents and a copy of the final packet.

A PDF can make a multi-page packet easier to inspect. For preparation help, see faxing paper documents without a fax machine and faxing a PDF without printing. A file extension alone does not guarantee readability: inspect the actual pages.

Use the cover page to route your response

LowFax.com always includes a cover page. Identify the receiving department or named contact, use a brief subject such as “Response to document request,” and add the reference information the recipient asks for. Include a useful reply contact.

Place identifiers where the CRA instructs you to place them. Do not add extra private information merely to make the cover more detailed. The cover page helps route the packet; it does not replace the requested forms or supporting evidence.

Send the packet from your browser

1. Open LowFax.com's sending form and enter your sender details.
2. Select Canada, enter the confirmed fax number, and check the recipient information.
3. Complete the cover-page fields and upload the final document.
4. Review the actual page count and displayed Canadian destination charge.
5. Pay and submit, then keep the delivery confirmation with the sent file.

LowFax.com is a browser-based sending service. You do not need a fax machine or a monthly sending subscription. Choose the submission method that meets the CRA's instructions; if its online portal fits your situation, fax is not mandatory.

Count the cover page before checking the price

Charges depend on the actual page count and destination country. A nine-page attachment plus LowFax.com's included cover page is a ten-page fax. Ten attachment pages plus that cover page make eleven total pages. File size in megabytes does not determine the charge.

Canada has its own rates. Check the total displayed after selecting Canada, rather than applying a US price to a Canadian submission.

Keep transmission and processing separate

A successful delivery notice records transmission to the destination fax system. It does not establish that the CRA has reviewed the evidence, accepted your claim, or met a processing deadline.

Keep the exact file sent, the destination, and the receipt together. Follow the CRA's instructions for checking the status of the response. If a send fails, check the number and error information before repeating the submission.

Compare the submission routes in your letter

Fax is useful when it is an accepted route and your packet is ready to send. It is not automatically better than an authenticated portal. Compare the options the CRA gives you before choosing one.

These records describe different events. A portal confirmation, fax receipt and postal tracking update should not be treated as interchangeable proof that the CRA has finished reviewing your case. Use the office's follow-up instructions for that question.

A worked example: replying with several attachments

Imagine your letter asks for evidence covering a specified period, and you have six pages of supporting documents plus a one-page explanation. This is an example of organizing a packet, not a list of evidence required for every review.

First, compare each attachment with the request. Check that the dates fall within the requested period and that the scans contain the information you mean to provide. Put the explanation first if that suits the recipient's instructions, then arrange the evidence in the same order as the letter.

Your seven attachment pages plus LowFax.com's cover page make eight fax pages. If you later add a two-page document the CRA also requested, the attachment becomes nine pages and the full fax becomes ten. Recount after changes rather than using the total from an earlier draft.

Save that final packet separately from the source scans. When the receipt arrives, store it with this exact version. You can then identify what you sent if the office asks for clarification.

A simple cover-message example

Adapt this routing message to your letter. Replace the bracketed entries, and include only the identifiers the CRA requests.

To: [department or named contact]
Subject: Response to document request dated [date]
Reference: [reference requested by the CRA]
Attached: [brief list of documents]
Reply contact: [your appropriate contact details]

This is a suggested routing format, not an official CRA form. If the letter specifies wording, a required form, or a different place for identifiers, follow that instruction. Keep the cover concise so the receiving staff can identify the purpose quickly.

What changes when you are outside Canada?

Your location does not remove the need to follow the receiving office's instructions. Verify the destination and confirm any uncertainty about an overseas-accessible number before preparing a time-sensitive send. A number printed on a letter should still be checked for its intended purpose.

For a deadline, record the date the office gives you rather than assuming a time zone or a processing rule. If the deadline is unclear or you need more time to collect documents, contact the office using the details in the request. Do not rely on a sending service to interpret the CRA's deadline for you.

Troubleshooting before sending again

If the file does not upload, open it locally and check that it is the completed document rather than a cloud sharing link. If it is password-protected, obtain a sendable copy you are authorized to use. A screenshot of the first page is not a substitute for the whole document.

If transmission fails, compare the entered number with the letter and review the error details. If the number is correct but the endpoint remains unavailable, ask the recipient about the appropriate alternative. If transmission succeeds but the office cannot locate the packet, provide the date, destination and receipt through its approved follow-up channel before deciding whether to resend.

Common questions

Can I send from the US or another country?

You can prepare and submit a fax through a browser while abroad. Confirm that the recipient accepts fax for your request and that the designated number can be reached by the sending service.

Can I fax any Canadian tax return this way?

This article covers supporting documents requested by the CRA. Check the current filing instructions for your specific return or form; a fax option for a review response does not establish a general filing option.

Do I need to add my own cover sheet?

LowFax.com already includes one. If the recipient requires a separate routing form, include that required form in your attachment and count it as an additional page.